#include <bits/stdc++.h>
using namespace std;

char s[105];

int main(){
    scanf("%s", s + 1);
    int n = strlen(s + 1);
    char c[2] = {'i', 'o'};
    int ans = 0;
    for(int i = 1, j = 0; i <= n; ){
        if(s[i] != c[j]) ans++;
        else i++;
        j ^= 1;
    }
    printf("%d\n", ans);
    return 0;
}